Iraqi officials say they have asked U.S. forces to release six of eight Iraqi female prisoners, but they say the move is not related to the demand of a militant group that kidnapped an American journalist.

The U.S. military has not said whether it would release the six prisoners.

Al Jazeera television aired a video Tuesday from militants holding American journalist Jill Carroll, who was kidnapped January 7 in Baghdad. The abductors threatened to kill Carroll unless all female Iraqi prisoners in U.S. custody were released within 72 hours.

Wednesday, gunmen in Baghdad ambushed an Egyptian-owned telephone company Iraqna's convoy, killing at least six security guards. Officials said two African employees traveling in the convoy are missing and feared kidnapped.